Are we to force everyone to publish a newspaper or otherwise make public their opinion on every issue? What happened to privacy and mind your own business? If someone doesn't want to have a gun(newspaper)(car)(eat meat)(vote)(----) as long as it doesn't involve their actual attack on another person then it is their right. They do not have a right to demand I conform to their way.
The warning sign is to protect the children.
That turns out not to be correct. While it's not a right per se, but rather a delegated power, Congress, and most state governments as well, has been granted the power to do just that, and as has been pointed out, they did, in the 1792 Militia Act.
Now whether that's good public policy is up for debate of course, as it every other act of Congress, but they do indeed have the power to require you to own a gun. They also have the power to provide exemptions for the religiously scrupulous, or the just plain squeamish, if they so choose.
As I recall a town in Georgia required every head of household to be armed. There was no penalty for not complying though. However the act was never, AFAIK, found to have exceeded their powers. That was just a small town council. Your state legislature or the Congress can do the same, and put teeth in it. Maybe they'd require a "fine" to help pay for guns for those who wish to comply with such a law, but cannot afford a gun. That, or something very like it, has been done in the past as well.